The needs assessment and case history intake form completed at the beginning of the appointment is an integral part of the hearing test and consultation. During the intake, the audiologist will identify the needs and desired outcomes for the patient in order to present realistic and appropriate treatment options. Treatment options can vary between hearing aids or other assistive listening technologies, medical intervention with a family doctor or Ear Nose and Throat (ENT) physician, and discussing communication strategies to assist with day to day hearing challenges. Sometimes, the treatment is a combination of all three. Identifying a patient’s needs and reason for visit is crucial as two individuals with the same hearing loss can experience very different challenges. For example, while one patient with a mild hearing loss struggles to hear the television and their grandchildren, another patient with the exact same loss may only have difficulty hearing in the presence of a lot of background noise (e.g, live sporting event or busy pub). Identifying the specific communication challenges of the patient, and their goals for improvement, allows our audiologists to tailor the treatment plan to the patient, and present solutions that meet their needs specifically.
Following the needs assessment and case history, the hearing test begins and is broken down into the following parts:
An otoscope (device used to examine the outer ear and ear drum) is the first step of the hearing test. Examination of the ear canal checks for potential infections, abnormalities with the eardrum, or whether a wax build up is present. If a wax build up is present, and the ear drum not visible as a result, wax removal is usually recommended prior to beginning the measurement of hearing thresholds. Wax removal is available at the clinic and can usually be completed during the same appointment.
This step of the hearing test helps identify the middle ear status by determining whether the eardrum moves in response to a low pitched sound. When the low pitched sound is emitted, the air pressure in the ear canal changes; the sensation experienced by the patient is similar to the pressure changes that occur when a plane is taking off or landing. While the pressure in the canal changes, the movement of the eardrum is noted. Tympanometry is one part of the puzzle that determines type of hearing loss, and whether the hearing loss is permanent in nature.
Air conduction Thresholds
Finding air conduction thresholds is the next step in determining the level of hearing loss for a patient. The audiologist will begin to play beeps between 250 hz (low pitch) to 8000 hz (high pitch) to determine the softest sound level a patient can hear at each tone. This range of pitches is used as they encompass the sounds necessary for day-to-day communication. This allows a patient’s “threshold” of hearing to be recorded. The patient is usually asked to say “yes” or push a button every time they hear the beep. Air conduction results help the audiologist understand the second piece of the puzzle: the quietest level a patient can hear when sound is passing through the outer ear and middle ear.
Bone Conduction Thresholds
Bone conduction is the next piece of the puzzle in determining the type and degree of hearing loss. During this stage of the hearing test appointment, the audiologist will place a metal headband with a bone oscillator onto the patient’s head. The bone oscillator will be placed behind the patient’s ear, on the mastoid bone. With this part of the test, the outer and middle ear is bypassed, and the inner ears response to sound is checked and recorded. Similar to the air conduction component, beeps are played at different pitches, and the patient is instructed to respond once they hear them. Once again, the softest sound heard is recorded.
Bone conduction is an integral part of the hearing test battery as it informs the audiologist what type of hearing loss is present. If the results of the bone conduction test are better than the air conduction (meaning the inner ear hears better than the outer and middle), there is an obstruction in the middle or outer ear preventing the transmission of sound. This could be a result of impacted wax, an ear infection, or middle ear bones that are not functioning properly. Conversely, if the cochlea or inner ear hears the same as the outer and middle ear, the hearing loss is permanent in nature and requires hearing aids for treatment.
Speech testing is completed at Toronto Hearing Consultants as part of the hearing test battery in both quiet and in noise. Completing speech testing in noise is crucial for determining how much a patient struggles in situations resembling restaurants or parties; a standard test battery usually only includes speech testing in quiet. This will not address patient concerns of difficulties hearing in noise, which is usually the first sign of hearing loss and what brings patients into the clinic for a test.
a) Speech Recognition Threshold: (SRT): 2 syllable words are played to the patient, and they are asked to repeat them back. The goal is to find the softest decibel or volume level at which the patient is able to repeat the 2 syllable words back. The results of SRT should validate the air conduction threshold results discussed previously on this page.
b) Word Recognition Score (WRS): WRS testing involves having the patient repeat back the last word of a sentence. The sentences are played at the most comfortable volume level for the patient, and allow the audiologist to gather information on the integrity of the auditory system. Two patients with the same hearing loss can have very different WRS scores: one patient may score 100% of the words correct, while the other patient may score 50% of the words correct. WRS scores are critical in helping the audiologist understand how a patient will perform with hearing aids. In the example above, the patient scoring 50% will perform worse with hearing aids than the patient scoring 100% as there is permanent damage to the auditory system that hearing aids cannot reverse. It is important to note that early intervention with hearing aids can preserve word recognition scores, which arguably is the most important score on the hearing test for predicting success with hearing aids.
c) Speech-In- Noise Testing: Many patients come in due to difficulties hearing in background noise, as this can be the first sign of permanent hearing loss. Evaluating results of speech understanding through creating a “cocktail party effect” in the hearing booth helps the audiologist determine appropriate hearing aid selection if required and counsel the patient on why they are struggling to hear in background noise.
The results of the hearing test are then plotted on an audiogram and reviewed with the patient during the consultation phase of the appointment. The results of the hearing test are discussed in relation to the needs assessment completed at the beginning of the appointment and recommendations for hearing aids or medical intervention are determined.